RUI: Self-organization and the Acquisition, Representation, and Processing of Language

University Of Richmond, Richmond VA

Investigators

Abstract

An ordinary adult speaker has active control of tens of thousands of words in any given language. Unlike a dictionary that lists words alphabetically, the mental dictionary organizes words in the mind in complex ways according to their uses in language, for example, their grammatical and semantic functions. This research will address how such organization arises in childhood, settles in adulthood, and sometimes breaks down in disordered minds. The research will provide an alternative approach to current neural network models of language, because it aims at developing a cognitively and neuropsychologically plausible model that relies on self-organizing principles. Self-organization, a dynamic process of human learning, allows the learner to gather information about the "input space" (i.e., the limits, constraints, and possibilities of things) and to continuously organize the information in ways optimal for the task at hand. Building on Li's developmental lexicon model (DevLex), the new model will incorporate properties of self-organization, Hebbian learning, lexical co-occurrence learning, and dynamic growth. These computational properties should make the model well suited for the study of the human mental lexicon, its structure, representation, and processing in children, normal adults, second language learners, and brain-injured patients. The model will attempt to account for a wide variety of phenomena in language use. In particular, its design characteristics will permit the evaluation of important problems from a number of domains: (1) the development of structurally organized representation as a function of learning the linguistic input, and the impact of the organizational structure on linguistic generalization (child language acquisition); (2) the distinct versus integrated nature of bilingual lexicon, and crosslinguistic differences in bilingual lexical representation and acquisition (bilingual language processing); (3) the development of lexical ambiguity and grammatical ambiguity, and the processing of ambiguity in patients (lexical ambiguity processing); (4) the interaction between orthography, phonology, and semantics in reading acquisition, and the crosslinguistic differences in normal reading and developmental dyslexia (normal and impaired reading); and (5) the acquisition of category-specific representation, and the structure of lesioned semantic representations in patients (category-specific language impairment). Results from the modeling of these aspects will provide significant insights into theoretical and empirical issues in psycholinguistics and cognitive science. Understanding of normal and disordered processes in different languages will also have significant implications for language education.